Described herein are toners for use in forming and developing high gloss images in electrostatographic, including xerographic, apparatuses. In embodiments, the toner is produced using emulsion aggregation processes. In embodiments, the toner exhibits improvement in toner tribo, charging, life performance, and print performance.
Emulsion aggregation toners can be used in electrophotography, including printing, copying, scanning, faxing, and the like, and including digital, image-on-image, and the like. The toner particles herein, in embodiments, can be made to have relatively uniform sizes, are nearly spherical in shape, and are environmentally friendly. U.S. patents describing emulsion aggregation toners include, for example, U.S. Pat. Nos. 5,370,963, 5,418,108, 5,290,654, 5,278,020, 5,308,734, 5,344,738, 5,403,693, 5,364,729, 5,346,797, 5,348,832, 5,405,728, 5,366,841, 5,496,676, 5,527,658, 5,585,215, 5,650,255, 5,650,256, 5,501,935, 5,723,253, 5,744,520, 5,763,133, 5,766,818, 5,747,215, 5,827,633, 5,853,944, 5,804,349, 5,840,462, 5,869,215, 6,803,166, 6,808,851, 6,824,942, 6,828,073, 6,830,860, 6,841,329, 6,849,371, 6,850,725, 6,890,696, 6,899,987, 6,916,586, 6,933,092, 6,936,396, 6,942,954, 6,984,480, 7,001,702, 7,029,817, 7,037,633, 7,041,420, 7,041,425, 7,049,042, 7,052,818, 7,097,954, 7,157,200, 7,160,661, 7,166,402, 7,179,575, 7,186,494, 7,208,253, and 7,217,484, each incorporated herein by reference in its entirety.
One main type of emulsion aggregation toner includes emulsion aggregation toners that include styrene acrylate resin. See, for example, U.S. Pat. No. 6,120,967, incorporated herein by reference in its entirety, as one example.
Emulsion aggregation techniques typically involve the formation of an emulsion latex of the resin particles, which particles have a small size of, for example, from about 5 to about 500 nanometers in diameter, by heating the resin, optionally with solvent if needed, in water, or by making a latex in water using an emulsion polymerization. A colorant dispersion, for example of a pigment dispersed in water, optionally also with additional resin, is separately formed. The colorant dispersion is added to the emulsion latex mixture, and an aggregating agent or complexing agent is then added to form aggregated toner particles. The aggregated toner particles are optionally heated to enable coalescence/fusing, thereby achieving aggregated, fused toner particles.
U.S. Pat. No. 5,462,828 describes a toner composition that includes a styrene/n-butyl acrylate copolymer resin having a number average molecular weight (Mn) of less than about 5,000, a weight average molecular weight of from about 10,000 to about 40,000, and a molecular weight distribution of greater than 6, that provides improved gloss and high fix properties at a low fusing temperature.
Traditionally, emulsion aggregation toners have not included charge control agents. This is an issue especially in high-volume machines that print more than six thousand copies per cartridge change. Problems with incorporation of charge control agents into emulsion aggregation toner include that traditional charge control agents have large particle sizes. Because of the large size, it has been difficult to incorporate the charge control additive into the toner particles during processing.
Therefore, it is desired to provide a charge control agent that has a smaller particle size and is easier to incorporate into the toner particles during emulsion aggregation processing. It is further desired to provide a toner having most or all of improved charging, tribo, gloss, print performance, and life performance.